1. Field of the Invention
The present invention relates to nozzles for fuel injectors, and more particularly to the poppets of such nozzles.
2. Description of the Related Art
Because the shape and direction of the plume of fuel exiting fuel injectors influences the efficiency of fuel combustion, some conventional fuel injectors include features that affect the shape and direction of the exiting plume. For example, some conventional fuel injectors include a projection that extends beyond the extremity of the exit of the fuel injectors, i.e., downstream of a valve seat of the fuel injectors. The exiting plume generally follows a path defined by the external surface of the projection. In this manner, the shape and direction of the exiting plume may be controlled.
Although such projections generally control the shape and direction of the plume, irregular deposits tend to form on the surface of the projection. For example, carbon and other combustion related deposits tend to form on the surface of the projection at a location immediately downstream of the valve seat of the fuel injectors. These deposits affect the flow of the plume over the projection and thus adversely affect the shape of the plume. If the fuel injector acts as a fuel metering device, these deposits may also adversely affect the quantity of metered fuel. Some conventional fuel injectors include features that tend to reduce the development of deposits, such as a necked portion and a hollowed-out projection. One benefit of these features is that they reduce the area through which heat in the projection can dissipate to the remainder of the air assist fuel injector and thus help maintain the projection at a sufficiently high temperature to burn off carbon and other deposits on the projection. Despite the relative successes of the above-noted configurations, some amount of deposits still form on the projections, especially at lower fueling levels and/or cooler combustion temperatures.
In light of the above-described problems associated with the delivery of fuel from conventional fuel injectors, the embodiments of the present invention strive to provide poppets for fuel injectors that are less susceptible to deposit formation.
Other objects, advantages and features associated with the embodiments of the present invention will become more readily apparent to those skilled in the art from the following detailed description. As will be realized, the invention is capable of other and different embodiments, and its several details are capable of modification in various obvious aspects, all without departing from the invention. Accordingly, the drawings in the description are to be regarded as illustrative in nature, and not limitative.